ProSpection™ Process Camera: Design Considerations

Posted on July 19th, 2023

The new Delta Controls ProSpection™ Process Camera is designed for continuous online inspection of the sulfur recovery unit (SRU). The primary design considerations for the process inspection camera include achieving the best view of the vessel’s interior, the camera’s usability and reliability, and most importantly the camera assembly’s safety.

A wide-angle lens placed at the refractory hot face with an insertable probe assembly provides the most useful view of the critical components of the vessel interior.  A number of significant challenges for this design were taken into consideration by the Delta Controls design team.  To overcome the material, corrosion, and temperature challenges, the camera design incorporates a patent pending thermal regulation system that uses water or air circulated through a series of channels to accurately regulate the probe’s temperature between the sulfur dewpoint corrosion and high temperature sulfidation limits, as well as maintain the camera circuitry within its temperature limits. Furthermore, the thermal regulation system maintains the lens temperature above sulfur’s freezing point to prevent lens occlusion.

The camera probe assembly is designed to be inserted through an isolation valve while a vessel is online and is either left installed indefinitely for long term monitoring or used for a temporary inspection. A flanged seal assembly mounts to a three-inch or larger nozzle flange and incorporates multiple redundant seals to allow for the camera to insert and retract without process leakage. As an added safety feature, a nitrogen supply applies a positive back pressure to the seals that is higher than the process pressure. 

To automate the insertion and retraction of the camera probe assembly, the ProSpection inspection camera utilizes a pneumatically driven extraction system that actuates the camera into and out of the vessel through the flanged seal assembly. This system allows for failsafe features to optimize the camera for long-term operation. The camera can automatically order its own retraction from the process for any number of fault conditions such as loss of coolant, rising camera temperature, loss of power, or loss of instrument air. As an additional fail-safe feature, the system also contains an onboard air tank with enough air capacity to safely remove the camera in the event of an air supply loss.